Abstract
Quantum state discrimination is a fundamental task having many applications in quantum information processing. However up to now there has been no rigorous formulation for discriminating -qudit states. In this article we provide a geometric method to obtain minimum error discrimination for -qudit states. By using the geometric approach to minimum-error discrimination for -qudit states, we supply the condition for the existence of optimal measurement that can be composed of null operators, which gives a key understanding for discriminating -qudit states. Furthermore we present how the number of nonzero operators for optimal measurement can be reduced. Applying our method to symmetric -qudit states we obtain optimal measurements, which are different from known ones.
- Received 14 March 2014
DOI:https://doi.org/10.1103/PhysRevA.90.022330
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